[Strawbale] Waterproof splash back in Lime plaster

[josephbecker at riseup.net]

I have a project where we are planning on taking lime plaster all the way
down to the ground.  This is in the Pacific NW and we get a lot of rain,
we have 2 ft overhangs and will have drainrock at ground all arou nd the
base.

We want to make the lower 18-24 inches splash resistant and extra
washable. The owner of the house does not want a color or transition line
separating the splash zone from the upper portion of the plaster.  This
makes it more difficult.

The things we have thought of..

Hydraulic lime scratch coat for the splash back. This would be covered
with a standard lime finish over the whole wall.

Applying a waterproofing agent (similar to foundation waterproofing
agents). Preferably one that soaks in so that we could lime wash.
Could we apply lime washes of any such treatment?

Has anyone done worked with lime plaster in this way or have nay ideas?

Thanks.
Best Regards,

Joseph Becker